Fetal monitor with automatic CTG analysis Overtone 6900 is designed to monitor the condition of the fetus and mother. Advanced functionality allows the monitor to be used in prenatal diagnostics, during and after childbirth. The Overtone 6900 is a fetal singleton pregnancy monitor. Exceptional information content, ergonomics, and ease of use make the fetal mother and fetus monitor available for use by personnel of any level of training.